1. Field of the Invention
The present invention relates to an in vitro assay for characterization of the leukocyte adhesion cascade. More specifically, the invention relates to a leukocyte adhesion and migration assay using a microfluidic apparatus.
2. Description of Related Art
The leukocyte adhesion cascade, a multistep process mediated by a series of receptor-ligand interactions, is important to many physiological and pathophysiological processes of the body. A number of in vitro models have been developed to study different aspects of the leukocyte adhesion cascade and to develop and test anti-inflammatory agents and other drugs. Flow chambers have been developed to study rolling and adhesion phenomena, and Boyden and transwell chambers have been used for migration studies.
Flow chambers provide physiological shear but cannot model transmigration. Transwell and Boyden chambers do not account for fluid shear and size/topology observed in-vivo or provide real-time visualization of leukocyte migration, measure leukocyte migration semi-quantitatively, and are labor intensive. No experimental model currently resolves rolling, adhesion and migration in a single assay. As a consequence, understanding of the leukocyte adhesion cascade and anti-inflammation drug development has been limited. For example, a leukocyte migration inhibitor in Boyden chambers may fail to work in realistic flow shear. The method and apparatus of the present invention provide a rapid assay for anti-inflammatory markers and drugs targeted to affect the leukocyte adhesion cascade.